The genus Heilungia Prynada (Cycadopsida) in the Late Cretaceous floras of the Okhotsk-Chukotka volcanic belt (Northeastern Russia)

New species Sequoia ochotica Yudova et Golovn. (Pinopsida, Cupressaceae) from the Turonian-Coniacian deposits of the Arman and Chingandzha Formations of the Okhotsk-Chukotka volcanic belt is described based at morphological features of leaves and shoots. Two other Late Cretaceous species of this genus: S. minuta Sveshn. from the Vilyui River basin of Eastern Siberia and S. tenuifolia (Schmalh.) Sveshn. et Budants. from the New Siberian Islands have comparable shoot morphology, but these species were described based at epidermal features.

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The distribution of Sphenobaiera biloba Prynada in the Cretaceous of Northeastern Asia

Palaeobotany ◽

10.31111/palaeobotany/2018.9.18 ◽

2018 ◽

Vol 9 ◽

pp. 18-31

Author(s):

N. V. Nosova ◽

L. B. Golovneva

Keyword(s):

River Basin ◽

Volcanic Belt ◽

Northeastern Russia ◽

Eastern Siberia ◽

Northeastern Asia ◽

Epidermal Structure ◽

Northern Asia ◽

Lena River ◽

Chukotka Volcanic Belt ◽

Volcanogenic Deposits

A revision of Sphenobaiera biloba Prynada from Northeastern Asia is based on restudy of the type material from the Zyryanka River Basin (Prynada’s collection), as well as additional specimens from the type locality (Samylina’s collection) and collections from the Ul’ya and Anadyr rivers. A new extended diagnosis of S. biloba based on the leaf morphology and epidermal structure is proposed. Geographic and stratigraphic distribution of this species in Northern Asia is discussed. S. bilobais known in the Aptian of Eastern Siberia (Lena River Basin) and from the early-middle Albian to Coniacian of northeastern Russia. In the Late Cretaceous this species was considered as relict and related with volcanogenic deposits of the Okhotsk-Chukotka volcanic belt.

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Tectonic and chronostratigraphic implications of new 40Ar/39Ar geochronology and geochemistry of the Arman and Maltan-Ola volcanic fields, Okhotsk-Chukotka volcanic belt, northeastern Russia

Geological Society of America Bulletin ◽

10.1130/b25340.1 ◽

2004 ◽

Vol 116 (5) ◽

pp. 637 ◽

Cited By ~ 37

Author(s):

Jeremy K. Hourigan ◽

Vyacheslav V. Akinin

Keyword(s):

Volcanic Belt ◽

Northeastern Russia ◽

Volcanic Fields ◽

Chukotka Volcanic Belt

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Paleomagnetism of the Late Cretaceous ignimbrite from the Okhotsk-Chukotka Volcanic Belt, Kolyma-Omolon Composite Terrane: Tectonic implications

Journal of Geodynamics ◽

10.1016/j.jog.2015.03.003 ◽

2015 ◽

Vol 91 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Yo-ichiro Otofuji ◽

Haider Zaman ◽

Gen Shogaki ◽

Hanae Seki ◽

Vladimir F. Polin ◽

...

Keyword(s):

Late Cretaceous ◽

Volcanic Belt ◽

Tectonic Implications ◽

Chukotka Volcanic Belt

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New Paleomagnetic Data on Late Cretaceous Chukotka Volcanics: the Chukotka Block Probably Underwent Displacements Relative to the North American and Eurasian Plates after the Formation of the Okhotsk-Chukotka Volcanic Belt?

Izvestiya Physics of the Solid Earth ◽

10.1134/s1069351321020014 ◽

2021 ◽

Vol 57 (2) ◽

pp. 232-246

Author(s):

I. E. Lebedev ◽

P. L. Tikhomirov ◽

A. M. Pasenko ◽

B. Eid ◽

F. Lhuillier ◽

...

Keyword(s):

Late Cretaceous ◽

North American ◽

Volcanic Belt ◽

Paleomagnetic Data ◽

The North ◽

Chukotka Volcanic Belt

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The Oloy floristic assemblage from the Cretaceous deposits of the Il’guveem river head, Northeastern Russia

Palaeobotany ◽

10.31111/palaeobotany/2015.6.68 ◽

2015 ◽

Vol 6 ◽

pp. 68-79

Author(s):

L. B. Golovneva

Keyword(s):

Volcanic Belt ◽

Taxonomic Composition ◽

Northeastern Russia ◽

Endemic Plants ◽

Sedimentary Deposits ◽

Chukotka Volcanic Belt ◽

Cretaceous Deposits

The Oloy floristic assemblage comes from volcanic-sedimentary deposits of the Teleneut Unit, distributed in the Il’guveem river head, at the Oloy, Great Anuy and Yablon Rivers interfluve area. This area belongs to the Anadyr segment of the Okchotsk-Chukotka volcanic belt (Belyi, 1977). The Oloy floristic assemblage consists of 15 species. Equisetopsida: Equisetum sp. Polypodiopsida: Cladophlebis sp., Coniopteris sp., Tchaunia tchaunensis Samyl. et Philipp. Czekanowskiopsida: Phoenicopsis ex gr. angustifolia Heer. Cycadophytes: Heilungia oloensis Samyl. et Philipp., Taeniopteris sp., Pterophyllum sp. Ginkgoopsida: Ginkgo sp., Sphenobaiera sp. Pinopsida: Pagiophyllum zhuravlevii Golovn., Araucarites sp., Taxodium sp., Sequoia sp., Pityophyllum sp. Among them gymnosperms predominate. Angiosperms are not revealed. Cycadophytes are represented by three genera (Heilungia, Taeniopteris and Pterophyllum). Taxonomic composition of the Oloy floristic assemblage most closely resembles the composition of the Chaun flora, which comes from the Coniacian deposits of the Chaun Group of Central Chukotka. From 15 species of the Oloy assemblage 13 species are common with the Chaun ones (besides Taeniopteris иPterophyllum). Among common taxa there are the characteristic endemic plants of the Chaun flora: Tchaunia tchaunensis and Pagiophyllum zhuravlevii. The great systematic similarity of these floras indicate that they were even-aged and belonged to the single phytogeographic area – the Chukotka subprovince of the Mountain Okchotsk-Chukotka province (Golovneva, 2014b).

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Amplitude of paleosecular variations during the Cretaceous superchron: Okhotsk-Chukotka Volcanic Belt, high latitudes

10.5194/egusphere-egu21-13171 ◽

2021 ◽

Author(s):

Elizaveta Bobrovnikova ◽

Ivan Lebedev

Keyword(s):

Late Cretaceous ◽

Geomagnetic Field ◽

Volcanic Belt ◽

Time Interval ◽

High Latitudes ◽

Magnetic Minerals ◽

Geological Time ◽

Russian Science ◽

Virtual Geomagnetic Pole ◽

Chukotka Volcanic Belt

Studying of paleosecular variations (PSV) over geological time allows us to characterize not only the behavior and evolution of the geomagnetic field, but also to estimate the rate of formation of large igneous provinces (LIP). In order to use this paleomagnetic tool, the amplitude of paleosecular variations during the corresponding time interval has to be known, but for the end of the Cretaceous superchron, in particular for high latitudes, such the data sets are extremely small. Our study is aimed at obtaining a limit on the PSV amplitude for Late Cretaceous in order to use these data to estimate the rate of formation of the Okhotsk-Chukotka Volcanic Belt.The formation of a paleomagnetic record in volcanic flows occurs by acquiring a thermal remanent magnetization (TRM) during their cooling below the Curie temperature of the magnetic minerals. Direction of this TRM can be used for calculation of the virtual geomagnetic pole (VGP), which characterizes the direction of the geomagnetic field at a given time and place. The angular dispersion of virtual geomagnetic poles (VGP scatter, Sb) is generally accepted as a measure of the paleosecular variations and uses to assess the duration of volcanic section formation. If the volcanic section was formed for a long time (more than 10 000 years), then the amplitude of the recorded geomagnetic variations will correspond to the expected dispersion for a given latitude. In the case of significantly higher eruption rates, the amplitude of the recorded PSV will be lower than it is predicted by the model for a given latitude.During the 2019-2020 field seasons paleomagnetic studies were carried out on a number of Late Cretaceous volcanic sections of the Okhotsk-Chukotka Volcanic Belt located in the Bilibinsky District of the Chukotka Region. VGPs and their scatter were calculated for 79 flows of the Kupol object. Preliminary results show that the amplitude of PVS in the Cretaceous for high latitudes of the northern hemisphere was close to that for the last 5 million years (Sb=21.4, [19.0; 23.9]).The work is supported by the Russian Science Foundation grant N 19-47-04110.

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The Chingandzha flora of the Okhotsk-Chukotka volcanic belt

Palaeobotany ◽

10.31111/palaeobotany/2019.10.13 ◽

2019 ◽

Vol 10 ◽

pp. 13-179

Author(s):

L. B. Golovneva

Keyword(s):

River Basin ◽

Volcanic Belt ◽

Flowering Plants ◽

Sedimentary Deposits ◽

North East ◽

The North ◽

Magadan Region ◽

Chukotka Volcanic Belt ◽

Systematic Composition ◽

Coastal Lowlands

The Chingandzha flora comes from the volcanic-sedimentary deposits of the Chingandzha Formation (the Okhotsk-Chukotka volcanic belt, North-East of Russia). The main localities of the Chingandzha flora are situated in the Omsukchan district of the Magadan Region: on the Tap River (basin of the middle course of the Viliga River), on the Kananyga River, near the mouth of the Rond Creek, and in the middle reaches of the Chingandzha River (basin of the Tumany River). The Chingandzha flora includes 23 genera and 33 species. Two new species (Taxodium viligense Golovn. and Cupressinocladus shelikhovii Golovn.) are described, and two new combinations (Arctopteris ochotica (Samyl.) Golovn. and Dalembia kryshtofovichii (Samyl.) Golovn.) are created. The Chingandzha flora consists of liverworts, horsetails, ferns, seed ferns, ginkgoaleans, conifers, and angiosperms. The main genera are Arctop teris, Osmunda, Coniopteris, Cladophlebis, Ginkgo, Sagenoptepis, Sequoia, Taxodium, Metasequoia, Cupressinocladus, Protophyllocladus, Pseudoprotophyllum, Trochodendroides, Dalembia, Menispermites, Araliaephyllum, Quereuxia. The Chingandzha flora is distinct from other floras of the Okhotsk-Chukotka volcanic belt (OCVB) in predominance of flowering plants and in absence of the Early Cretaceous relicts such as Podozamites, Phoenicopsis and cycadophytes. According to its systematic composition and palaeoecological features, the Chingandzha flora is similar to the Coniacian Kaivayam and Tylpegyrgynay floras of the North-East of Russia, which were distributed at coastal lowlands east of the mountain ridges of the OCVB. Therefore, the age of the Chingandzha flora is determined as the Coniacian. This flora is assigned to the Kaivayam phase of the flora evolution and to the Anadyr Province of the Siberian-Canadian floristic realm. The Chingandzha flora is correlated with the Coniacian Aleeky flora from the Viliga-Tumany interfluve area and with other Coniacian floras of the OCVB: the Chaun flora of the Central Chukotka, the Kholchan flora of the Magadan Region and the Ul’ya flora of the Ul’ya Depression.

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